NAS

Mark Hahn hahn at physics.mcmaster.ca
Tue Jul 2 09:15:18 PDT 2002


> > I remember is 16 TB.  I presume that's actually 2^(31+9),
> 
> Some useful conversions:

oops, my mistake was actually the 31+9=44 thing ;)

hmm, so the 16 TB thing must be an ext2/3 limit derived
from at most 4k blocks, and triple-indirect-ed-ness.
afaik, the block layer in <= 2.4 still uses 512B sectors (2^9)
so the block-level limit is either 2^(31+9), 2^(32+9) 
or something huge like 2^(63+9).

hmm, from a quick look at include/linux/blkdev.h:
struct request {
...
        unsigned long sector;

so the answer is 2^(32+9) = 2 TB (I used bc this time!)




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